TIME-ALIGNMENT MEASUREMENT FOR HYBRID HD RADIO tm TECHNOLOGY
AssigneeiBiquity Digital Corporation
InventorsBrian W. Kroeger, Paul J. Peyla
Life of this patent
Estimating the term…
Abstract
A method for processing a digital audio broadcast signal in a radio receiver, includes: receiving a hybrid broadcast signal; demodulating the hybrid broadcast signal to produce an analog audio stream and a digital audio stream; and using a normalized cross-correlation of envelopes of the analog audio stream and the digital audio stream to measure a time offset between the analog audio stream and the digital audio stream. The time offset can be used to align the analog audio stream and the digital audio stream for subsequent blending of an output of the radio receiver from the analog audio stream to the digital audio stream or from the digital audio stream to the analog audio stream.
Claims19
A method for processing a digital audio broadcast signal in a radio receiver, the method comprising:
- receiving a hybrid broadcast signal;
- demodulating the hybrid broadcast signal to produce an analog audio stream and a digital audio stream;
- using a normalized cross-correlation of envelopes of the analog audio stream and the digital audio stream to measure a time offset between the analog audio stream and the digital audio stream;
- blending an output of the radio receiver from the analog audio stream to the digital audio stream or from the digital audio stream to the analog audio stream;
- phase-adjusting the digital audio stream;
- and
- using the phase-adjusted digital audio stream to temporarily replace input digital audio frames during blend ramps used in the blending of the output of the radio receiver.
(canceled)
-19. (canceled)
A radio receiver comprising:
- processing circuitry configured:
- to receive a hybrid broadcast signal;
- to demodulate the hybrid broadcast signal to produce an analog audio stream and a digital audio stream;
- to use a normalized cross-correlation of envelopes of the analog audio stream and the digital audio stream to measure a time offset between the analog audio stream and the digital audio stream;
- to compute a coarse envelope cross-correlation over a first range of lag values to locate a vicinity of the time offset;
- and
- to subsequently compute a fine envelope cross-correlation over a second range of lag values, wherein the second range of lag values is narrower than the first range of lag values.
25-26. (canceled)
Dependencies are inferred from the claim text.